Wearable Sensor for Continuous Noninvasive Monitoring of Pulse Pressure Blood pressure and pulse pressure are among the most commonly measured parameters to assess cardiovascular function. However, existing solutions for continuous noninvasive monitoring require cumbersome cuffs and are unsuitable for true ambulatory use. We propose to develop a compact, cuff-less, wearable patch sensor for continuous noninvasive monitoring of pulse pressure for human use. The sensor will be adhered like a band-aid to the skin over the carotid or brachial artery and will use pulsed Doppler ultrasound to continuously measure blood flow velocity, arterial diameter with a 1 micron resolution and local pulse transit times with 0.1 millisecond resolution. These measurements are input to an algorithm to estimate pulse pressure for each heartbeat without the need for calibration. The sensor can also estimate systolic, diastolic, and mean pressure with intermittent calibration against an independent measurement. An added benefit of the sensor is the simultaneous measurement of other useful hemodynamic parameters: heart rate, local pulse wave velocity, and arterial diameter. The sensor will consist of a multi-element high frequency ultrasound transducer, pulsed Doppler electronics for measurement of blood flow velocity and arterial wall displacement, an embedded microcontroller with software for calculation of hemodynamic parameters, and a bi-directional wireless link for telemetry. During phase I we will 1) build a multi-element Doppler transducer and bench top wired Pulsed Doppler electronics, 2) validate the technique and algorithms with in-vivo animal studies, and 3) demonstrate pulse pressure measurement in humans by comparison with snapshot measurements by expert operators using auscultation, and by comparison with continuous measurements from commercially available cuff based devices. During phase II we will refine the transducer, electronics and algorithms, add wireless capability, perform validation with human studies, and miniaturize the transducer and electronics to fit into a compact wearable adhesive patch (40mm x 20mm x 10mm). The final result will be a cost-effective commercial product that addresses an unmet need in the market for a compact cuff-less wearable noninvasive pulse pressure monitor and will have wide applicability in home care (white coat hypertension, chronic cardiac disease monitoring), in hospital care (ICU, ER), in portable use (ambulances, disaster medicine, battle field triage), and for remote health monitoring of personnel (battle field, hazardous industrial locations, and space). PUBLIC HEALTH RELEVANCE: Blood pressure and pulse pressure are among the most commonly measured parameters to assess cardiovascular function. However, existing solutions for continuous noninvasive monitoring require cumbersome cuffs and are unsuitable for true ambulatory use. The proposed work will result in a compact, cuff-less, wearable patch sensor for continuous non-invasive monitoring of pulse pressure in humans. This device will have wide applicability in home care (white coat hypertension, chronic cardiac disease monitoring), in hospital care (ICU, ER), in portable use (ambulances, disaster medicine, battle field triage), and for remote health monitoring of personnel (battle field, hazardous industrial locations, and space).